In this study, a new approach to enhance methane (CH4) production from organic substrates in anaerobic digestion (AD) has been discovered. That is, the addition of elemental sulfur (S0) particles into the AD system promotes the synergistic growth of elemental sulfur disproportionation bacteria, acidogenic bacteria and methanogenic archaea, thus facilitating hydrolysis, acidogenesis and methanogenesis. The efficacy of this AD enhancement pathway was confirmed in AD experiments with glucose as a model organic substrate. The results demonstrated that CH4 production in the AD system increased considerably with S0 dosages ranging from 20 mg/L to 300 mg/L. Two gas production peaks appeared at dosages of 20 mg/L and 180 mg/L, where the total CH4 production increased by 2.1 times and 2.5 times, respectively compared with the control group. However, inhibitory effect was observed for S0 dosages above 300 mg/L. The chemical states of S, the microbial community and the abundance of key functional enzymes in the AD system were analyzed. The results showed that S0 addition increased the relative abundance of Dethiobacteraceae, Caldatribacterium, Anaerolineaceae, Methanobacterium and Methanosaeta and considerably increased the abundance of key functional enzymes, such as dehydrogenase, D-glucosidic glucosidase, pyruvate synthase and acetyl-CoA deacetylase. The enrichment of these microorganisms and functional enzymes was strongly positively correlated with the production of volatile fatty acids and CH4, demonstrating that S0 addition effectively enhances methanogenesis during AD.

中文翻译：

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通过添加元素硫增强厌氧消化


在这项研究中，发现了一种在厌氧消化 （AD） 中增强有机底物产生甲烷 （CH4） 的新方法。即元素硫 （S0） 颗粒加入 AD 系统，促进元素硫歧化细菌、产酸菌和产甲烷古菌的协同生长，从而促进水解、酸化和产甲烷。这种 AD 增强途径的疗效在以葡萄糖为模型有机底物的 AD 实验中得到证实。结果表明，当 S0 剂量范围为 20 mg/L 至 300 mg/L 时，AD 系统中的 CH4 产生显着增加。在 20 mg/L 和 180 mg/L 的剂量下出现两个产气高峰，其中 CH4 总产生量分别比对照组增加了 2.1 倍和 2.5 倍。然而，对 S0 剂量高于 300 mg/L 观察到抑制作用。分析 AD 系统中 S 的化学状态、微生物群落和关键功能酶的丰度。结果表明，S0 添加增加了脱硫杆菌科、Caldatribacterium、Anaerolineaceae、Methanobacterium 和 Methanosaeta 的相对丰度，并显著提高了脱氢酶、D-葡萄糖苷酶、丙酮酸合酶和乙酰辅酶 A 脱乙酰酶等关键功能酶的丰度。这些微生物和功能酶的富集与挥发性脂肪酸和 CH4 的产生呈强正相关，表明 S0 添加可有效增强 AD 期间的甲烷生成。